Majority of the vehicle systems are configured to operate with a wide variety of fuels, including fuels with a range of alcohol concentrations, such as various gasoline-ethanol blends, including E10, E85, etc. Thus, components of fuel systems, including fuel filler pipes (also known as fuel inlet pipes), which are utilized for transferring fuel from an external source to the fuel tanks, and the fuel tanks, are subjected to corrosive effects of ethanol and acids in the fuel. In addition to corrosion by fuel, the fuel system components may be exposed to environmental corrosion conditions, such as humidity, salt, etc., on the exterior. Corrosion leads to rust formation and mechanical degradation of the fuel system components.
Further, fuel systems include anti-siphoning devices, which are utilized for preventing theft of fuel from the tanks via the fuel filler pipes. The anti-siphoning devices are coupled to the fuel filler pipe. Thus, fuel and external environmental factors mentioned above also corrode the anti-siphoning device. Further, the corrosion not only causes mechanical degradation of the anti-siphon device, the coupling between the fuel filler pipe and the anti-siphon device is weakened. Further, corrosion that may develop within the tank may clog fuel injectors and fuel filters. Still further, some vehicle systems (e.g., trucks) utilize a metal fuel filler cap that is threaded onto the fuel filler pipe. The fuel and the external environmental factors may also induce galvanic corrosion between the metals of the fuel filler pipe and the cap.
The inventors herein have recognized the above-mentioned issues. In one example, the issues described above may be addressed by a manufacturing method for a fuel tank and a fuel filler pipe, comprising: coupling a device to the fuel filler pipe with one or more first welding joints, then coating the coupled fuel filler pipe and device with a first coating; and then, coupling the coated fuel filler pipe including the device to the fuel tank with one or more second welding joints. In this way, corrosion protection is provided by coating the fuel filler pipe, the device, and the coupling between the pipe and the device.
As an example, a device, such as an anti-siphoning device, is welded internally to a fuel filler pipe. After welding, the fuel filler pipe and the anti-siphoning device assembly, including the internal welds are coated for corrosion protection. After coating, the assembly is welded externally to the fuel tank. By coating the fuel filler pipe and the device assembly including the fuel filler pipe, the device, and the welds coupling the fuel filler pipe and the device, corrosion of the pipe, the device and the coupling is reduced, thereby reducing mechanical degradation.
In another example, a manufacturing method for a fuel tank and a fuel filler pipe comprises welding an anti-siphon device to an interior of the fuel filler pipe, then coating the welded fuel filler pipe and the device with an electroless nickel coating; and then welding the coated fuel filler pipe and the device to the fuel tank. The electroless nickel coating is applied to the internal and the external surfaces of the fuel filler pipe including external threads on the fuel filler pipe that are utilized for receiving a metal fuel filler cap, the anti-siphon device, and the welds between the fuel filler pipe and the device.
By utilizing the electroless nickel plating process, nickel coating of substantially constant thickness may be achieved on all coated surfaces. In particular, the fuel filler pipe and/or the device may include surfaces that form complex geometric and/or non-geometric structures such as sharp edges, holes, ridges, tabs, deep recesses, protrusions, conical structures, cylindrical structures, spindle-shaped structures, slots, seams, threads, etc. By utilizing electroless nickel plating, uniform coating on all surfaces may be achieved. As a result, in addition to uniform corrosion protection for all coated surfaces, visual appearance of the pipe and the device assembly is improved.
Further, by utilizing electroless nickel plating on the exterior threads of the fuel filler pipe, galvanic corrosion between the metals of the fuel filler pipe and the cap is reduced. Still further, a desired thickness of the coating that reduces interference with threading of the metal cap onto the filler tube may be achieved by the electroless nickel plating process.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.